High definition multimedia interface (HDMI) is a widely used interface for transferring uncompressed video data and compressed or uncompressed digital audio data between a HDMI-capable source device and a HDMI-capable sink device. In some examples, an HDMI-capable source device may be a set-top box, a DVD or Blu-Ray Disc player, a digital video recorder, a personal computer, a video game console, a “smart” phone or tablet, and the like. An HDMI-capable sink device may be a digital television, a digital audio receiver, a computer monitor, a video projector, or other audio and/or video display device. HDMI enables lossless transmission of video data between the source and sink devices. HDMI is limited, however, by the wired connections that are necessary to provide the bandwidth needed to transmit the uncompressed video data.
In addition to supporting HDMI, a source device, especially a mobile source device such as a “smart” phone or tablet, may also support Wireless Display (WD) or WiFi Display (WFD) systems, e.g., according to the Miracast™ standard. In a WD system, the source device transmits multimedia data, such as audio video (AV) data, audio data, and/or video data, over a wireless connection to one or more of the sink devices participating in a particular wireless display session. The wireless connection may be established directly between the source device and the one or more sink devices without the need for cables or a network connection. The multimedia data may be played back at both a local display of the source device and at each of the displays of the sink devices.
In some cases, so called “wireless HDMI” has been introduced. These systems typically require the use of compression to wirelessly transmit the video data and/or audio data between the source device and an HDMI-capable client device. The HDMI-capable client device may be referred to as a stick, a fob, a pod, or the like. The HDMI-capable client device is physically connected to the sink device via an HDMI connector, and wirelessly connected to the source device via a wireless connection. In this scenario, the client device may be configured to perform video and/or audio encoding and decoding for wireless transmission with the source device, and further configured to perform HDMI-based data, control and security processing for wired transmission with the sink device.